1. Field
Aspects of the present invention relate to a touch screen panel and a fabrication method thereof.
2. Description of the Related Art
A touch screen panel is an input device capable of inputting a user's instruction by selecting instruction contents displayed on a screen of an image display device, or the like, with a human's hand or an object.
To this end, the touch screen panel may be provided on a front surface of the image display device to convert a contact position directly contacted by the human hand or the object into an electric signal. Therefore, the instruction contents selected at the contact position may be recognized as an input signal.
Since the touch screen panel may be substituted for a separate input device connected to the image display device, such as a keyboard or a mouse, application fields thereof have been gradually extended.
Example types of the touch screen panel include a resistive type touch screen panel, a photosensitive type touch screen panel, a capacitive type touch screen panel, and the like. Among these, the capacitive type touch screen panel senses a change in capacitance formed between a conductive sensing pattern and neighboring other sensing patterns, a ground electrode, or the like, when a human hand or an object contacts the touch screen panel, thereby converting a contact position into an electric signal.
The capacitive type touch screen panel may include first sensing cells coupled to each other and formed in a first direction, and second sensing cells coupled to each other and formed in a second direction. Here, adjacent first sensing cells may be electrically connected to each other through a first connecting line, adjacent second sensing cells may be electrically connected to each other through a second connecting line, and the first and second connecting lines may overlap each other (but are insulated by an insulating layer interposed therebetween).
Particularly, a structure in which the first and second sensing cells are formed on the same layer and the first or second connecting lines are formed on the insulating layer in a bridge pattern to couple the first or second sensing cells to each other, respectively, has been used.
Here, the connecting lines formed on the insulating layer may be made of the same material as that of the sensing cell, for example, a transparent conductive material (such as, an indium tin oxide (ITO), or a low resistance metal material).
However, when the above-mentioned structure (that is, the sensing pattern structure in which the connecting lines are included in the bridge pattern) is used, the bridge pattern may be observed (or viewed), which may interfere with an image displayed on the image display device.
To reduce this interference, the quantity of material used in the bridge pattern and/or dimensions of length, width, and thickness thereof may be reduced (e.g., made maximally small). However, such a design increases resistance of the bridge pattern, which causes other problems, such as a deterioration of sensing sensitivity and vulnerability to external electrostatic discharge (ESD).